Weights and Measures Act 1985

Sections 1(2), 8(1).

SCHEDULE 1 U.K. Definitions of Units of Measurement

Part I U.K. Measurement of Length

Imperial units

Mile =	1760 yards.
YARD =	0·9144 metre.
Foot =	1/3 yard.
Inch =	1/36 yard.

Metric units U.K.

Kilometre =	1000 metres.
METRE	is the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second.
Decimetre =	1/10 metre.
Centimetre =	1/100 metre.
Millimetre =	1/1000 metre.

Part II U.K. Measurement of Area

Imperial units U.K.

Acre =	4840 square yards.
SQUARE YARD =	a superficial area equal to that of a square each side of which measures one yard.
Square foot =	1/9 square yard.

Metric units U.K.

Hectare =	100 ares.
Decare =	10 ares.
Are =	100 square metres.
SQUARE METRE=	a superficial area equal to that of a square each side of which measures one metre.
Square decimetre =	1/100 square metre.
Square centimetre =	1/100 square decimetre.
Square millimetre =	1/100 square centimetre.

Part III U.K. Measurement of Volume

Metric units U.K.

CUBIC METRE =	a volume equal to that of a cube each edge of which measures one metre.
Cubic decimetre =	1/1000 cubic metre.
Cubic centimetre =	1/1000 cubic decimetre.
Hectolitre =	100 litres.
LITRE =	a cubic decimetre.
Decilitre =	1/10 litre.
Centilitre =	1/100 litre.
Millilitre =	1/1000 litre.

Part IV U.K. Measurement of Capacity

Imperial units U.K.

GALLON =	4·546 09 cubic decimetres.
Quart =	1/4 gallon.
Pint =	1/2 quart.
Gill =	1/4 pint.
Fluid ounce =	1/20 pint.

Metric units U.K.

Hectolitre =	100 litres.
LITRE =	a cubic decimetre.
Decilitre =	1/10 litre.
Centilitre =	1/100 litre.
Millilitre =	1/1000 litre.

Part V U.K. Measurement of Mass or Weight

Imperial units U.K.

POUND =	0·453 592 37 kilogram.
Ounce =	1/16 pound.
Ounce troy =	12/175 pound.

Metric units U.K.

Tonne, metric tonne =	1000 kilograms.
KILOGRAM=	is the unit of mass; it is equal to the mass of the international prototype of the kilogram.
Hectogram =	1/10 kilogram.
Gram =	1/1000 kilogram.
Carat (metric) =	1/5 gram.
Milligram =	1/1000 gram.

Part VI U.K. Definitions of Certain Units Which May Not be Used for Trade

Measurement of length

Furlong =	220 yards.
Chain =	22 yards.

Measurement of area

Square mile =	640 acres.
Rood =	1210 square yards.
Square inch =	1/144 square foot.

Measurement of volume

Cubic yard =	a volume equal to that of a cube each edge of which measures one yard.
Cubic foot =	1/27 cubic yard.
Cubic inch =	1/1728 cubic foot.

Measurement of capacity

Bushel =	8 gallons.
Peck =	2 gallons.
Fluid drachm =	1/8 fluid ounce.
Minim =	1/60 fluid drachm.

Measurement of mass or weight

Ton =	2240 pounds.
Hundredweight =	112 pounds.
Cental =	100 pounds.
Quarter =	28 pounds.
Stone =	14 pounds.
Dram =	1/16 ounce.
Grain =	1/7000 pound.
Pennyweight =	24 grains.
Ounce apothecaries =	480 grains.
Drachm =	1/8 ounce apothecaries.
Scruple =	1/3 drachm.
Metric ton =	1000 kilograms.
Quintal =	100 kilograms.

Part VII U.K. Measurement of Electricity

1.	(a) AMPERE	is that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section and placed 1 metre apart in vacuum, would produce between these conductors a force equal to 2 x 10–7 newton per metre of length.
	(b) OHM	is the electric resistance between two points of a conductor when a constant potential difference of 1 volt, applied between the two points, produces in the conductor a current of 1 ampere, the conductor not being the seat of any electromotive force.
	(c) VOLT	is the difference of electric potential between two points of a conducting wire carrying a constant current of 1 ampere when the power dissipated between these points is equal to 1 watt.
	(d) WATT	is the power which in one second gives rise to energy of 1 joule.
2.	Kilowatt	= 1000 watts.
	Megawatt	= one million watts.